Cartridge fuse



March 2,1926.

- F. A. FELDKAMP CARTRIDGE FUSE Filed Feb. 20,

- INVENTOR. fizdfegz'afli'ekfmyv, BY gf ATTORNEYS.

I I I I l I I l I I I I I I Patented Mar. 2, 11 92 6.

" T s :;PATENT, IEQFFICE 1 f I rnnnnnicx A. FELDKAMP,

I or NEWAR NEW Jnnsnyl icanrnrnen rnsn. 5

v L'Apifllcation file'dj ebruary 20, 1924. S eriaI'No. 694,002.

TOaZZ away concern-r5 I Be it knowmthat I, FREDnRIoK A.- Fnnm KAMP, a citizen of'theiUnit'ed States, res1ding at vNewark, inithe county of Essexfand State of New J ersey, have invented; certain ,new andnseful Improvements inCart-ridge -E'uses; and'I do h'erebydeclare the following to be a full, clear, and. exact description of the invention, such as will enableothers skilled in, the art to which it'iappertains to make and'use the same, referencebeing had to the accompanylng draw ngs; and to characters of reference-marked thereon, which form apartfof thisispecification;

r provements in ele'ctricrfuse, devices; and the I inve'nti onhas' reference; morepaTticularly,

to improvements in zcartridge .fu'se devices provided a, with the, blade :type; i of. terminal 'coiitactfmembers. A

The invention has for'its principal object to provide a novel construction of cartridge fuse provided with means for rigidly holding the blade contacts against movement or displacement, so that the gap between the opposed internal ends of the blade conment is maintained at the desired predetertacts, which is bridged by the fusible ,ele-

nii'ned dimension; thus avoiding accidental variations or: changes gof the ggap dimension with' the consequent change in the fuse rating,;for,incrcase yingthellength of the gap weakens the amperelrating of the fuse, and decrease in the'length of the gapstrength' ens the ampere rating of the "fuse. This invention' also contemplates the use,'- in connnection with the blade-positioning and retaining' v means, of means for .hermetically sealingthe]cartridgeso that the internal elementwithithe consequent vaporization of pressure, induced by the blowing of the fuse the meta-l of said fusefelement, willtend' to decrease 1the;,jump ing distance of the arc and ,brin about a prompt, quenching of the latter. v in this connectionitis desired to employ a suitable Tinert filler, powder, and the invention also has'for a further object to "provideiinconnection with the blade contact holdingimeans, an arrangen'lent which will permit of-the easy and rapid filling and packing of the, cartridge-shell with the pow- I I: and holding means-therefor arevinplace.

()ther objects of'this invention, not atthis time more particularly enumerated; will be VThis invention'relates, generally,-to im "clearly understood from the following :de-

tailed description'of the same.

lVith the various objects of this invention in View, the, same consists, primarily, in the I novel construction of cartridge fuse proscribed, and then finally embodied in the claims which. are appended heretor Theinv'ention is clearly illustrated in the accompanying. drawings, in which and embodyin'g the principles of-this inven 131011; F gure 2 1s a transverse section taken vided with blade type terminals or, contacts Figure 1 is afllongitudinal vertical section through a cartridge fusemade'accordlng to online 2' -2 in Figure 1, anddrawn. on an enlarged scale; Figure 3; is another trans-Q verse section takenon line3,-3 in Figure 1,

also drawn on an enlarged scale; and Figuret is a fragmentary longitudinal section, taken on l1ne in Figure '1, and also drawn on an enlarged scale.

a Figure 5 is an inner face view of a modi fie d form of blade"contact positioning and holdingmeans; Figure 6 is a side elevation ofthe same; and Figure 'Z'is a longitudinal section thereof, taken on line. 77 in Figure6p," V

Similar characters of-reference are em ployed in all of theherei'n'above described views, to 1 indicate corresponding parts. 7

'Referring'now to said drawings, the reference character 1 indicates the tubular cartridge shell or casing which is madeof any suitable electrically non-conductive material.

' Thereference character'2 indicates the blade terminals or contact members of the device, the inner end portions 3 of which extend respectively into opposite ends of said shell or casing 1. -Each blade terminal or contact is provided in its longitudinal edges with transversely oppositeindented slots or notches 4, which are spaced forwardly or [outwardly from the inner termination of the same, so as to determinethe desired distance of projection of theinner end portions 3 of the'blade terminal or contac't into the interior of the shell or casing.

each blade terminal or contact indesir'e The l'mean's for positioning and holcin i is substantially. equal tojthe externaldiameter of the: shell er -casing '1, sothat When assembled in the structure themarginal por tions of the wa her member "W111 restor abut upon the endof said shellor casing. "The diametricmarginal edge portion of each 'half-port-io1i 5 offthe Washer member )is out fziiwayfas at 6, to straddle the body of the *blade' terminal or Contact 2. In thus cutting away saidhalf portions 5 of the asher n'iemb'er to'ngues 'tfa'rc left at eachend-therej of which; when thehalf-portions 5' areas sembled-togetheriiii operative relation to the blade terminal or contact, enter the indented slots, or notches & so as to interlock with l the blade terminalgol' contact to thus hold thelatter againstlongitudinalplay or dis- 25:

placement. f-Eachfihalf-portion *5 r said washer member I is provided with a buttress 1mg 8,-, which is struck up -out oi then'maiii "*bjo'dy i thereof bordering 1 its 'diametric edge,

1 and then'turned zit-light; angles-tothe'plane ofthe Washer member.- "W hen thejhalf-por tions 5 of the Washer member are assembled together in operative relation to a bladeter- Qminil' or 'eontact gsaid buttress" lugs 8 respectively extend along and brace against the-res ective feces of the inner end portion 8 of said blade terminal'or "contact, thus securely and rigidlyholding the "latter --against lateral play ior displacement. In. thus'strikingfout 6f}the body of each halfportion; 5 015 the Washer member the said "buttress*lugs*8;the Washer member is at the i 'sametime provided 'With'jopenings-"9, which 7 may be employed as filling openingsfor the introductioninto the interiorofthe shell ror casing l an inert filler powder 10*after the blade terminals orcontacts andfwashermembers are ope'rative'ly positioned relatlve to" the shell or casing, whereby the operation o'f s'o filling the'shell r casingfisgreatly facilitated.

A-sultable fuse element 11 is {is e-mare and 'electrically interconnected betweenthe inner end portions 3 of the opposite blade terminals or contactsfi. I

In order to retain the blade terminals or contacts 2with-"theirpositioning and holding' washer ,members'fin proper assembled relatioirto the ends of the'shell orvc'asing 1', ferrules or caps .12 are provided which are telese'opicallv engaged'over the endsof the shellior-casiiiig 1, and the end Walls ofwh'ich o arefslotted to peifmit' -tl1e external end portions of the blade' termlnals or contacts to projectoutwardly' therethrough. The said ferrules or caps 12 are se ured against dis 7 preferably? fire-proof material,- such, :for example;assheet'asbestos. 'Thesealing' Wash ers are disposed intermediate. the end all'j of each ferrule or cap 12 aiid the outer face members, v'Said sealingwashers 14: 'are slotted to permit-the outward projection therethroughfofjthe;external ends of said blade caps 12 are applied to' the shell'or casin endsfthe sameare pressed firmly down to squeeze or compress'the sealing washers, 14 so thatf'thelatter arevery tightly pressed 2' around the blade terminals or contacts so.

I11 practice 7 the v operations of assembling theVarious-parts of the novel'cartridge' fuse "arecarriedonas fOIloWsz- The fuse elementllis connected between the inner end portions" of thejblade ter-. 1 1 minals or fc'ontacts,andone end of the shell or casing is first closed by a ferrule or capj w 12 after the positioninghndholding Washer member andsealing Washer are properly assembled with the fbled'e l't'erminal or con tact'arra'nged at said end. {'Ihepositioning; and holding Washer for theopp'ositc blade placement from the endsof the shell casv s b y stakes ,13 orb-yeny other suitable means of'fasteningor-attachment.

r I 'find it highly des rable to] hermetically seal the cartridge fusein some instances and 1 to accomplish such "endli provide a sealing irasher= 14 of a suitable compressible and of the blade positioningandjholding Washer terminals or fcontacts;v I V-Vhen the ferrules 'ior that'all crevices around the latter are tightly closed an'd since the bledeterminals or contacts are; rigidly held against both lateral 1 and longitudinal play orfjdisplaccment the termin or contact is assembled; therewith so'asto abut against the opposite endoffthe shell or-"casinfg. The cartridge: fuse isthen 'upturned o'n' its closed or capped end; and the filler' powder 10 is thereupon introduced 5 through the "filling openings 'of the then upper exposed positioning and holding asher: member, -Wl1ll6* the cartridge :i'fu se' is subjected to 1 vibratory motion which com-;

[pacts the fillingpowder aroundthefuse" element and internal-ends of the blade terminels or contacts." In thismanncr the fill V ing powder will imbed-a'll'the internal parts including the buttress lugs 8, and; all'necessity of forcing par ts into' relative positious after the shell or casingis filled withi powder filled with the powdenin the manner: above described, the sealing Washer andopposite ferrule-or cap are assembled witlrthe upper end ofthe shell or'ca'sing, thus "completing the cartridge fuse.

The cartridge fuse in t its finished form is hermetically sealed,' and consequently not only Will the increased internal pressure pro duced theim-omentof blowing'ofjthe fuse element;-due to the gases produced by vaporizationhof: the fuse elen1ent,- tend to decrease thejumpingdistance of-the arcybut' vill also i causea much more :rapidfextinction of the arc; furthermore,*.the hot [gases :Will be con-- .i fined within the shell-l greasing :where they y can do In'o' harm, thus-{avoiding fire risks.

I Thehermetically' sealed oartridge'canbe employed'withoutfear of-over-pressure When a fuse element 'of high specific conductivityis employed; such, sfo'r example, like the fuse: elements/'1 described in prior Letters; Patent No; 1,473;284,' 1 dated November 6th;

1923,::and in my pending application for Letf'fters Patent Serial No.- 6-29,808, filed April; "4th, 1923. "'Ihesefuse elements consisting of 1' (copper are of the smallest'mas's for a given. amperaga fand 'therefore the pressure pro;

duced, when blowing under ashort 3 circuit,

is safely within the limitoftensilestrength 0f the shell'or ca-sing and Within the limit I of resistance to; displacement offered by the ferrules or; caps. }=The: filler powder in conjunction with a f-use'el'ement ofcomparative ly smalhmassalso p'laysa'part in reducing internal pressuresfwithin the range of safety. It'Willbe understood ,;however, that it'niay fbe desirable to employ thesnovel'means' for positioning and holding the blade terminals voil-contacts {Without regard to "Whether the V *eaftridgefusefis'of the hermetically sealed type or not; and consequently; as togthis' feature of my" invention I intend' tofjclaiin the same broadly for use Wit-h any kind {of oartridg-e'- fuse as Well asspecificallyiin. com- 'bination Witha' hermeticallysea-led cartridge .Ifuse as above described; 1 J I i 5* Referring now to-F i'nodified fformof positioning and holding j p to the external, diameter of. the tubular shell terminalorjVcOntactlZ "with fwhichflit iS iOi 5a v i therethrou'gh. Said blade-terminator conorcasin vvith Whi ch it} is to be used. I Said f main' body' ifs-provided {with a diametrically disposed slot l6 correspondingin dimensions to the crosssectional dimensions of the blade cooperate,"so that the lattei' -may; be inserted tact is'!provided gvvith(indented slotsor 1 notches 18in its opposite longitudinal-ledge portions-.1:Striimjk out of the" body of washer-memberso as to. respectively "border opposite sides of said slot 16, and respectivejlyladjacent to each endof the latter are upturned buttress lugs 19 which project in rplanes' at right angles-to the" laneof said washer memberiil} In thus stri ing up said This s buttress lugs 19, arc'uate concentric internal marginal. portions are provided to extend respectively in opposite directions from opposite sides of an adjacent to opposite ends of the slot-16. lnassemblingtheblade ter 'mi-nal or contact 17 with the Washer member thus formed,=,the former is inserted through I the slot 16 untiljits slots or notches 18 are I. respectively opposite theen-ds of said arcuate;

port-ions20, theposition being that shown by "the dotted lines .in Figure 5.f The blade ter- Yminalor contact is then given a quarter turn in the direction of the dotted'arrow 'in said 'Figure- 5, thuscausing the areuate portions 20 to enter the indented slots or'notches 18 to hold the blade terminal or-contact against longitudinaldisplacement;While-at the same I time engaginglthebuttress lugs 19 respec-. -tivelylagainst opposite sides or. facesof the blade terminal or contact to hold the same against lateral-play or displacement The f strikingv up of said buttress lugs 19 out of the body of the Washer member also provides thefilling openings 21 throughwhich a filler powder may be introduced into the shell or casing With Whichthe blade terminal or contact and the Washer member are used. After the modified form of washer members have been assembled 'with theblade terminals or contacts, the cartridge fuse parts are assembled together and completedxin the same 'manner as already'above vdescribed'w 1; In a cartridge fuse, a-tubular shell,

blade-terminals, end caps, and blade holding and .pOSltlOIlHlg Washer members engaged .between'the ends of said shellandsaid end caps, each WEtSllBl member having'port ons interlocked with a blade terminal ,.'to' hold theflla'tter against longitudinal displacement,

and each vwasher member having buttress I lugsfstruck up from the body thereof to respectively engage'and brace opposite sides of said'blade terminal. a V .2. In a cartridge fuse, a. tubular shell,

blade-terminals, ,end caps, and blade holdting and'spositioning Washer. members en gaged between the'ends of said shell and said endicaps, each Washermember having :portions'interlocked with a blade terminal to hold the latter against longitudinal dis-l placement and each :rvasher =member having. buttress lugs struck up from thebody 3 thereof. to respectively engageand brace op posite sides of'said blade terminal the upturning :of said. buttress lugs out of the 3 body 'of/said washer member providing openings in thelatterr-for ,the introduction therethrough into the interior of saidshell of a suitable filler powder'; I

In a cartridge fuse,- a tubular shelh blade-terminals, endcaps, and blade hold ing and positioning ashermembers engaged between the ends of saidshell and said end caps, each blade terminalhaving in its posite indented slots, each washer having to respectively engageuandv 'braceqopposite ifa'cesiof'said blade terminals portions engaged in said slots to hold said blade terminalagainstllongitudinal displacement', and-each 'Washer member Thavin'g buttress lugs 'stru ckup. from the' 'body thereof 4Q :In "a cartridge fuse, a; tubiilar shell,

blade-terminals, i end caps, .an d'iblade' holdingand positioning washer meinbersen-' gaged: betweenthei ends of said shell "and,

sa-i'd asher memberhavingstrnckupfnom :said e1'1d caps ,*-each blade terminal having 20 to respectively engage andfbrace it'opp'osit'e its longitudinal edge; portion: transversely opposite indented slots, each washer-having .p,ortio'ns engaged I :inis'ai'd {slots to hold 'sai d blade Iterminalaga'instelongitii dinal displace "faces of said bladeterminal, the upturning .of'said buttressrlugsout of th'exbody y of" saidavasher member-providing openings "in i the *latter": for the introdnctionfi there'- suitab'le filler'powder.

through into the interior'of said shell i'o'f "a fiise, a tubii lar l shell,

" 3 blade terininalsyend caps, ,and 'bladehold ing and positioning r washer finenibersj engag ed between the' ends of said shell and said end caps, each washer; member being diametrically di'vided to provide separable halves to embrace opposite sides'o'f said 7 longitudinal displacement'jand eachlialf .of g r W saicl'- wasl1er.men1ber'havingstrucknp fro1nits/inner diametric' marginalportio'n a but-' V i blade terminal, each. half of said; Washer "member having 2 portions interlocked fwith said bladetermi-n al toihold' the latter'agains t tress ylug," said buttress lugs being respec-' tively ieng agedi in bra'cingt relation 1'00 'oppoj site js'idevgfacesflof said'gbla'determinal,

. 6x11 mana e "fuse, a- 'tubiilar 1-311 11, *blade. terminals, end caps,-"andl blade'lholdgagedzlbetweengthe'endseiofgsaid shel'l and ing and positioningiqwasher Q members i en {said endicap's, each washerjinember' being fld iametrically divided to provide? separable halves ,to aemb race opposite sides-of said blade-terminal,' each half of"said .::washer" member having portionsinterlockedzwith ,w f said blade terminal to hold the latter; aga-inst longitudinaldisplacementyand each half of i --'s aid' \vashenmember havingi r'struck 11p from tress lug, .saidklbnttress*lugs v itlvelyia'engaged rinybracing.relaticni'to oppo- 1 its. inner diametriclmareina portion 'a :but-

em vrespec Isite side faces ofzisaid aiblade terminal, the

fuptn'rning' of said buttress lugs providing openings ingeaclr halfaof said Washer; inem- '1ber forftheintroduction therethrough into 7 -tl'1einterior of Qpovvdersk s q c,

' 17..Infagcartridge fu se, a tubularshell, blade terminals; endcaps, andiblade holding said shell-10f a suitable filler and. positionin longitudinal edge :p ortionstransversely 0p i being diametrically dividedtozprovide sepaof=eaclr half; of; said Washer being cutawayj qvith; tongnesat each end of said=dia1netric i edge; portions to 'enterj said indented Islots' its innenmarginalportionibordering a .facefj -0f said blade terminal abnttress-lug turned invvardly'at right angles to the plane of the washer member 2 and edgewis'e Ito the trace said blade terminal.-

ing and positioning washer v niembers, eng-aged between the ends-0f saidshell and, SEIlClBIlCl' caps, each blade termlnal havingin';

op'posite indented sl0ts, ;feaich Washer: member being vdiametrically"divided to, provide separabledialves', each'fdiametric'edge portion of; each half ofsaid. washerqbeing cutaway to embraoea blade terminalfland provided;

edgelyportionsi to enter; said; indented slots ;of said :blade terminal, and each half er said Washer member having struck up ,ifro'm its inner inarginal portionbordering-aiface {o'fgsaid blade terminal a buttress-lug turned a QinWardly :atgright angles ftQ the" plane of.

1 said bi t l lugs 2.;Pr vidie lem i s n of said shelliof a'suitable filler powder. a.

' 9. In a cartridge; fuse, a ;tubular ishell, vblade terminals, end caps,-rand' blade holding j "gitndinal edgeporti'ons transversely oppo- 1 site indented slots,- euzh'vvasher 'me'mberibeiing; diarnetrically:dividedfto. :provide 's'epa each half of said Washer-being cutaway: t0 embrace a blade terminal "and provided with ,tonguesateachend of jsaidtdiametric edge lportionsit'o; enter said 'indent efd slots of said member having ;struck-;up from; its c inner marginal; portion bordering: {a *face of said Washer, of comparatively compressible matetcompressed intermediate the end caps and iwaslier members engaged 5;" between'ithegends of said shell and saidendcaps, each blade terminal l12l.V1I1gf11 1- ,ltS

posite indented slots,weach Washer member rable l1alves,-: each. diam'etric edge portion to: embrace-Ia blade "terminal and provided of said blade terminal, and each-half- :of

8; In a cartridger'fuse, ajtilbular blade-terminals,rend' caps,fandfbladeihold 13 i": Y

its longitudinal edge portions transversely with tongues ateaoh end of said diametric I thej Washermember and edgewise to-i-tlie face QfQSELlCl blade terminal, "the npturning of each halt-Lofsaid washer-: niember for; the introduction therethrough into} the, interio and positioning washer membersfj engage between the ends of said shell and 'saidendcaps, each blade, terminal having in its lonrablehalves, each diametric edge portion of 129 blade terminal, "and each; half of said'washei i blade terminal a buttress-lngi turned ,in- V wardly iat' right anglesto the plane of the 1 a Washer member and ed'gewise to the face-of said blade terminal, and a slotted sealing rial. engaged over each blade terminalrand washer 4 members to 'hermetic'ally'seal theinterior of said} shell.

10. Inna cartridge v fuse,=a tubular shell,

blade-terminals,end capsgan'd blade holding and :positioning wa'sherimembers engaged,

" 7 between the ends of said shell and said end caps, each;washer member having portions.

interlockediwitlra blade terminal to hold the latterifagainst longitudinal displacement,

and "each washer. member having but-tress lugs'struck up from the body thereof to;

respectively engage and-brace opposite sides I of said blade terminal, and-1a slotted sealing washer ofcomparativel'y 'jcompressible matecompressed intermediate the end caps and rial,engaged over each blade terminal and 3 positioning-and holding washer members to hermeticallylseal the interior of said shell. I Y11."In"-a cartridge ;Euse, a tubular shell,

blade-terminals, end caps, and blade holding and positioning washer members engaged between the ends of said shell and said end icaps,-each blade terminal having in its lon- Hgitudinal edge portions transversely opposite indented slots each washer having portions engaged in said slots to hold said blade terminal against longitudinal displacement, "gand each. washer member havmg buttress i lugs strucknp fromQthebody thereof to respectivelyengage and brace opposite faces v or f'said blade terminal, (and slotted sealing V {washer of comparatively compressible mate engaged over; each blade terminal and,

compressed intermediate the end caps and positioning and holding washer members to I f'her'metically seal the i'nterior of said shell.

12. In a cartridge "fuse, a tubular shell, blade terminals,end caps, and blade holding and positioning washer members engaged betweenthe ends of said shell and said-end caps, each washer member, being diametrically divided to provide separable halves to I embrace opposite sides of said blade terminals, each halfof said washer member havingfportions interlocked with said blade terminal to hold the' -Iatter against longi tudinal displacement, and each halfof said v washer member having struck up from its inner diametric marginal portion abuttress lug, said buttress lugs beingrespectively engaged in bracing relation to opposite side faces of said blade terminals, and-a slotted sealing washer of comparatively compressiblematerial engagedover each blade ter minal and compressed intermediate theend caps and positioning andv holding washer members to hermetically seal the interior of said'shell; 1

13. In a cartridge fuse, a tubular shell," j

blade terminals,,endcaps, and blade holding and positioning washer members, engaged between the ends of said shell and said end" caps, each blade terminal having in its lon gitudinaledge portions transversely oppositevindented slots, each washer member being' diametrically divided'to provide separable halves, each diametric edge portion of each half of said washerbeing cutaway to embrace a blade terminal and provided with tongues at each end of said diametric edge portions to enter said-indented slots of said blade terminal,.and each half of said washer membenhaving struck up from its inner marginal portion bordering'a face of said blade terminal a buttress-lug. turned in; wardly at right angles' to the plane of the washer member and edgewise'to'the face oi said blade terminal, the upturnin'g-of said half of said washer member for the introbuttress lugs providing openings in each;

duction therethrough into the interior of said shell of a suitable filler powder, and a slotted sealing washer of comparatively blade terminal and compressed intermediate "compressible material engagedv over each the [end caps and positioning and holding washer membersato hermetically seal the in- :terior of said shell.

' In testimony that I claim the invention set forth above I have hereunto set my hand this lth day of February, 1924.

FREDERICK A, 'FELDKAMP. 

